Consolidate win/x dispatchers

ash/accelerators/accelerator_dispatcher.h

Index: ash/accelerators/accelerator_dispatcher.h
diff --git a/ash/accelerators/accelerator_dispatcher.h b/ash/accelerators/accelerator_dispatcher.h
index 1d5d75c1d13d5541a674b7404906d748dca5addc..fcc69f0e61fcb113c4efe722514df7e066f2a402 100644
--- a/ash/accelerators/accelerator_dispatcher.h
+++ b/ash/accelerators/accelerator_dispatcher.h
@@ -26,12 +26,8 @@ class ASH_EXPORT AcceleratorDispatcher : public MessageLoop::Dispatcher,
                                  aura::Window* associated_window);
   virtual ~AcceleratorDispatcher();
 
-#if defined(USE_X11)
-  virtual base::MessagePumpDispatcher::DispatchStatus Dispatch(
-      XEvent* xev) OVERRIDE;
-#elif defined(OS_WIN)
-  bool AcceleratorDispatcher::Dispatch(const MSG& msg) OVERRIDE;
-#endif
+  // MessageLoop::Dispatcher overrides:
+  virtual bool Dispatch(const base::NativeEvent& event) OVERRIDE;
 
   // aura::WindowObserver overrides:
   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;